Oak tree is an arrangement of sheets of MDF. The angles of the sheet are directly related to angles of leaves on oak trees and follow the ratio 2/5. This pattern is explained by Phyllotaxis. The term Phyllotaxis refers to the patterns on plants formed by the arrangement of repeated biological units. In nearly all cases, the Fibonacci Numbers and the Golden Ratio occur in these arrangements.

A Fibonacci spiral created by drawing circular arcs connecting the opposite corners of squares in the Fibonacci tiling; this one uses squares of sizes 1, 1, 2, 3, 5, 8, 13, 21, and 34.

A repeating spiral can be represented by a fraction describing the angle of windings leaf per leaf. Oak leaves will have an angle of 2/5 of a full rotation. In beech, the angle is 1/3, in poplar, it is 3/8, and in willow, the angle is 5/13. The numerator and denominator normally consist of a Fibonacci number and its second successor.

Leonardo da Vinci was the first to suggest that the adaptive advantage of the Fibonacci pattern in plants is to maximize exposure to dew. Current thinking supports this interpretation; exposure to rainfall and sunlight are also maximized.